2-30. A model for the fraction of micropipets operating within specifications after time t is Fraction within specifications =et(ln2)/tm where tm is the mean time between failure (the time when the fraction meeting specifications is reduced to 50% ). Suppose that tm=2.00 years. (a) Show that the equation predicts that the time at which 50% of micropipets remain within specifications is 2yr if tm=2.00yr. (b) Find the time t at which pipets should be recalibrated (and repaired, if necessary) so that 95% of all pipets will operate within specifications